bbb bbc bbe bbf bbk bbo bbs bbt bcb bcc bce bcf bck bco bcs bct be- beb bec bee bef bek beo bes bet bfb bfc bfe bff bfo bfs bft bkb bkc bke bkf bkk bko bks bkt bob boc boe bof bok boo bos bot bsb bsc bse bsf bsk bso bss bst btb btc bte btf btk bto bts btt c-- cbb cbc cbe cbf cbk cbo cbs cbt ccb ccc cce ccf cck cco ccs cct ce- ceb cec cee cef cek ceo ces cet cfb cfc cfe cff cfk cfo cfs cft ckb ckc cko cks ckt co- cob coc coe cof cok coo cos cot csb csc cse csf csk cso css cst ctb ctc cte ctf ctk cto cts ctt ebb ebc ebe ebf ebk ebo ebs ebt ec- ecb ecc ece ecf eck eco ecs ect eeb eec eee eef eek eeo ees eet ef- efb efc efe eff efo efs eft ekb ekc eke ekf eko eks ekt eo- eob eoc eoe eof eok eoo eos eot es- esb esc ese esf esk eso ess est etb etc ete etf etk eto ets ett fbb fbc fbe fbf fbk fbo fbs fbt fcb fcc fce fcf fck fco fcs fct feb fec fee fef fek feo fes fet ffc ffe fff ffk ffo ffs fft fkb fkc fkf fkk fkt fob foc foe fof fok foo fos fot fsb fsc fse fsf fsk fso fss fst ftb ftc fte ftf ftk fto fts ftt k-t kbb kbc kbe kbf kbk kbo kbs kcb kcc kce kck kcs kct ke- keb kec kee kef kek keo kes ket kfc kff kfo kfs kkb kkc kke kkk kks kkt kob koc koe kof kok koo kos kot ksb ksc kse ksf ksk kso kss kst ktb ktc kte ktf ktk kto kts ktt ob- obb obc obe obf obk obo obs obt oc- ocb occ ocf ock oco ocs oct oeb oec oee oef oeo oes oet of- ofb ofc ofe off ofo ofs oft okb okc oke okk oko oks oo- oob ooc oof ook ooo oos oot os- osb osc ose osf osk oso oss ost ot- otb otc ote otf otk oto ots ott sbb sbc sbe sbf sbk sbo sbs sbt scb scc sce scf sck sco scs sct se- seb sec see sef sek seo ses set sfb sfc sfe sff sfk sfo sfs sft sk- skb skc ske skf skk sko sks skt sob soc soe sof sok soo sos sot ss- ssb ssc sse ssf ssk sso sss sst stb stc ste stf stk sto sts stt tbb tbc tbe tbf tbk tbo tbs tbt tcb tcc tce tcf tck tco tcs tct te- teb tec tee tef tek teo tes tet tfb tfc tfe tff tfk tfo tfs tft tkb tkc tke tkk tko tks tkt to- tob toc toe tof tok too tos tot tsb tsc tse tsf tsk tso tss tst ttb ttc tte ttf ttk tto tts ttt